The present invention relates to a method for replacing the server and recovering from the fault when a fault has occurred in the server for a computer system.
When a fault has occurred in a currently used server while performing tasks in a computer system comprising multiple servers, the tasks being performed on that server come to a stop. Methods are therefore available to reduce the amount of operation down time and improve computer usability by replacing the server with another server and then continuing to perform the computer tasks.
An one fail over method for example is disclosed in JP 2006-163963 A which, when a fault occurs in the active server, a backup server not currently running a task, starts up a boot disk (logic unit) utilized by the active server where the fault occurred, in order to take over the tasks or duties of server where the fault occurred. In this method, when there are multiple active servers on a computer system, the backup server can take over the boot disk used by the active server where the fault occurred to allow fail over regardless of which server where the error occurred. This method is highly reliable since a small number of backup servers are prepared for a large number of active servers. Moreover, there is no need to form software such as an OS (operating system) in advance on the backup server. In other words, there is no need to contrive a backup server compared to fail over methods such as hot-standby.